On Fri, 2009-09-25 at 13:14 +0300, Heikki Linnakangas wrote: > Simon Riggs wrote: > > On Wed, 2009-09-23 at 19:07 +0300, Heikki Linnakangas wrote: > > > >> Rather than keep the numHeldLocks counters per-proc in proc array, I > >> think it would be simpler to have a single (or one per lock partition) > >> counter in shared memory in lock.c. It's just an optimization to make it > >> faster to find out that there is no loggable AccessExclusiveLocks in the > >> system, so it really rather belongs into the lock manager. > > > > What lock would protect that value? The whole purpose is to avoid taking > > the LockMgrLocks and to give something that is accessible by the locks > > already held by GetRunningTransactionData(). > > The lock partition lock (so we really need one counter per partition, a > single counter would need additional locking). We're already holding > that in LockAcquire/LockRelease when we need to increment/decrement the > counter.
Again: The whole purpose is to avoid taking those locks. Why would we put something behind a lock we are trying to avoid taking? -- Simon Riggs www.2ndQuadrant.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
